I watched all 5 episodes on television and it is very revealing, almost shocking. There are no taboes in this masterpiece.
The documentary is made by Germans, with Germans about Germans. It is unique in the sense that for the first time the transcripts of conversations between captive high ranking German officers have been released.
During their captivity in England (Trent Park Castle), all their conversations were secretely recorded on vinyl.
ZDF, the German producer, has a dedicated website with all 5 episodes in high quality, 45 minutes each, starting at the bottom of the page Teil 1. No subtitles but even if you don't understand a word of German it is still worth watching for the unique, often previously unreleased footage.